A small blade safe can hold hundreds of blades and it's like 4"x3"x3". Makes sense they thought the inside of drywall 5'x3'x1' would be fine. It can probably hold tens of thousands. Even with a new blade daily that's decades. And when you tear down the wall you're dealing with Sheetrock, nails and screws already. All that time would have dulled the incredibly thin blades.

This is all to say: it seems wild but was a decent idea.